Network Working Group T. Graf Internet-Draft Swisscom Intended status: Standards Track April 10, 2021 Expires: October 12, 2021 Export of MPLS Segment Routing Label Type Information in IP Flow Information Export (IPFIX) draft-ietf-opsawg-ipfix-mpls-sr-label-type-01 Abstract This document introduces additional code points in the mplsTopLabelType Information Element for IS-IS, OSPFv2, OSPFv3 and BGP MPLS Segment Routing (SR) extensions to enable Segment Routing label protocol type information in IP Flow Information Export (IPFIX). Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of Graf Expires October 12, 2021 [Page 1] Internet-Draft IPFIX MPLS Segment Routing Information April 2021 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. MPLS Segment Routing Top Label Type . . . . . . . . . . . . . 2 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 4. Operational Considerations . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction Besides BGP-4 [RFC8277], LDP [RFC5036] and BGP VPN [RFC4364], four new routing-protocols, OSPFv2 Extensions [RFC8665], OSPFv3 Extensions [RFC8666], IS-IS Extensions [RFC8667] and BGP Prefix-SID [RFC8669] have been added to the list of routing-protocols able to propagate Segment Routing labels for the MPLS data plane [RFC8660]. Traffic Accounting in Segment Routing Networks [I-D.ali-spring-sr-traffic-accounting] describes how IPFIX can be leveraged to account traffic to MPLS Segment Routing label dimensions within a Segment Routing domain. In the Information Model for IP Flow Information Export IPFIX [RFC7012], the information element mplsTopLabelType(46) describes which MPLS control plane protocol allocated the top-of-stack label in the MPLS label stack. RFC 7012 section 7.2 [RFC7012] describes the "IPFIX MPLS label type (Value 46)" sub-registry [IANA-IPFIX-IE46] where new code points should be added. 2. MPLS Segment Routing Top Label Type By introducing four new code points to information element mplsTopLabelType(46) for IS-IS, OSPFv2, OSPFv3 and BGP Prefix-SID, when Segment Routing with one of these four routing protocols is deployed, we get insight into which traffic is being forwarded based on which MPLS control plane protocol. A typical use case scenario is to monitor MPLS control plane migrations from LDP to IS-IS or OSPF Segment Routing. Such a migration can be done node by node as described in RFC8661 [RFC8661]. Another use case scenario is to monitor MPLS control plane migrations from dynamic BGP labels according to RFC8277 [RFC8277] to BGP Prefix- Graf Expires October 12, 2021 [Page 2] Internet-Draft IPFIX MPLS Segment Routing Information April 2021 SID according to RFC8669 [RFC8669] in context of Seamless MPLS SR [I-D.hegde-spring-mpls-seamless-sr]. Both use cases can be verified by using mplsTopLabelType(46), mplsTopLabelIPv4Address(47), mplsTopLabelIPv6Address(140), mplsTopLabelStackSection(70) and forwardingStatus(89) dimensions to get insights into o how many packets are forwarded or dropped o if dropped, for which reasons o the MPLS provider edge loopback address and label protocol By looking at the MPLS label value itself, it is not always clear as to which label protocol it belongs, since they could potentially share the same label allocation range. This is the case for IGP- Adjacency SID's, LDP and dynamic BGP labels as an example. 3. IANA Considerations IANA is requested to allocate four code points in the existing sub- registry "IPFIX MPLS label type (Value 46)" of the "IPFIX Information Elements" registry for IS-IS, OSPFv2, OSPFv3 and BGP Prefix-SID Segment Routing extensions. ------------------------------------------------------------------- | Value| Description | Reference | Requester | |---------------------------------------------------|-------------- | TBD1 | OSPFv2 Segment Routing | RFC8665 | [RFC-to-be] | |---------------------------------------------------|-------------- | TBD2 | OSPFv3 Segment Routing | RFC8666 | [RFC-to-be] | |---------------------------------------------------|-------------- | TBD3 | IS-IS Segment Routing | RFC8667 | [RFC-to-be] | |---------------------------------------------------|------------ | TBD4 | BGP Segment Routing Prefix-SID | RFC8669 | [RFC-to-be] | ------------------------------------------------------------------- Figure 1: Updates to "IPFIX MPLS label type (Value 46)" SubRegistry Note to IANA: o Please assign TBD1 to 4 to the next available numbers according to the "IPFIX MPLS label type (Value 46)" sub-registry [IANA-IPFIX-IE46] procedure. o Please replace the [RFC-to-be] with the RFC number assigned to this document. Graf Expires October 12, 2021 [Page 3] Internet-Draft IPFIX MPLS Segment Routing Information April 2021 Note to RFC-editor: o Please remove above two IANA notes. 4. Operational Considerations In the information element mplsTopLabelType(46), the BGP code point 4 refers to the label value in MP_REACH_NLRI path attribute described in section 2 of RFC8277 [RFC8277], and the BGP Segment Routing Prefix-SID code point TBD4 to the label index value in the Label- Index TLV described in section 3.1 of RFC8669 [RFC8669]. 5. Security Considerations There exists no extra security considerations regarding the allocation of these new IPFIX information elements compared to RFC7012 [RFC7012]. 6. Acknowledgements I would like to thank to the IE doctors, Paul Aitken and Andrew Feren, as well Benoit Claise, Loa Andersson, Tianran Zhou, Pierre Francois, Bruno Decreane, Paolo Lucente, Hannes Gredler, Ketan Talaulikar, Sabrina Tanamal, Erik Auerswald, Sergey Fomin, Mohamed Boucadair and Tom Petch for their review and valuable comments. 7. References 7.1. Normative References [RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model for IP Flow Information Export (IPFIX)", RFC 7012, DOI 10.17487/RFC7012, September 2013, . 7.2. Informative References [I-D.ali-spring-sr-traffic-accounting] Filsfils, C., Talaulikar, K., Sivabalan, S., Horneffer, M., Raszuk, R., Litkowski, S., Voyer, D., and R. Morton, "Traffic Accounting in Segment Routing Networks", draft- ali-spring-sr-traffic-accounting-04 (work in progress), February 2020. Graf Expires October 12, 2021 [Page 4] Internet-Draft IPFIX MPLS Segment Routing Information April 2021 [I-D.hegde-spring-mpls-seamless-sr] Hegde, S., Bowers, C., Xu, X., Gulko, A., Bogdanov, A., Uttaro, J., Jalil, L., Khaddam, M., and A. Alston, "Seamless Segment Routing", draft-hegde-spring-mpls- seamless-sr-04 (work in progress), January 2021. [IANA-IPFIX-IE46] "IANA IP Flow Information Export (IPFIX) Information Element #46 SubRegistry", . [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 2006, . [RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed., "LDP Specification", RFC 5036, DOI 10.17487/RFC5036, October 2007, . [RFC8277] Rosen, E., "Using BGP to Bind MPLS Labels to Address Prefixes", RFC 8277, DOI 10.17487/RFC8277, October 2017, . [RFC8660] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing with the MPLS Data Plane", RFC 8660, DOI 10.17487/RFC8660, December 2019, . [RFC8661] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S., Decraene, B., and S. Litkowski, "Segment Routing MPLS Interworking with LDP", RFC 8661, DOI 10.17487/RFC8661, December 2019, . [RFC8665] Psenak, P., Ed., Previdi, S., Ed., Filsfils, C., Gredler, H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF Extensions for Segment Routing", RFC 8665, DOI 10.17487/RFC8665, December 2019, . [RFC8666] Psenak, P., Ed. and S. Previdi, Ed., "OSPFv3 Extensions for Segment Routing", RFC 8666, DOI 10.17487/RFC8666, December 2019, . Graf Expires October 12, 2021 [Page 5] Internet-Draft IPFIX MPLS Segment Routing Information April 2021 [RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C., Bashandy, A., Gredler, H., and B. Decraene, "IS-IS Extensions for Segment Routing", RFC 8667, DOI 10.17487/RFC8667, December 2019, . [RFC8669] Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah, A., and H. Gredler, "Segment Routing Prefix Segment Identifier Extensions for BGP", RFC 8669, DOI 10.17487/RFC8669, December 2019, . Author's Address Thomas Graf Swisscom Binzring 17 Zurich 8045 Switzerland Email: thomas.graf@swisscom.com Graf Expires October 12, 2021 [Page 6]